1. Field of the Invention
The present invention relates to processing apparatus, a portable transmitter and a remote operation system, and particularly relates to processing apparatus to be installed in a to-be-equipped body such as a mobile body, a portable transmitter for remotely operating a plurality of functions provided in the to-be-equipped body, and a remote operation system including the processing apparatus and the portable transmitter.
2. Description of the Related Art
There has been hitherto known an apparatus for making control to lock/unlock a door of a vehicle or to start/stop an engine of the vehicle by remote operation. For example, in a system (so-called keyless entry system) for achieving remote operation for locking/unlocking a door of a vehicle, a radio wave transmitted from a transmitter portably carried by a user is received by an antenna of the vehicle and then, an ECU (Electronic Control Unit) mounted on the vehicle identifies a transmitted code and actuates a door lock/unlock actuator.
The system for achieving the remote operation for locking/unlocking a door of a vehicle has been invented and mainly aimed at solving difficulty in looking for a key hole of the door or inserting a key into the key hole in the dark at night or the like. Accordingly, as for the remote operation for locking/unlocking the door, a user will not feel so inconvenienced even if the remote operation can be achieved only near the vehicle. Therefore, very weak radio wave power to be transmitted from the transmitter being carried by the user may be sufficient.
On the other hand, the system for attaining the remote operation for starting/stopping an engine of a vehicle has been invented and mainly aimed at warming up the engine by operation from the inside of a house or a building. Accordingly, a user will feel inconvenienced if the remote operation for starting/stopping the engine cannot be carried out from a place at a certain distance from the vehicle. Therefore, it is desired that the radio wave power to be transmitted from the transmitter being carried by the user is somewhat high.
In addition, recently, a system which can carry out remote operation to lock/unlock a door of a vehicle and to start/stop an engine of the vehicle by use of a single transmitter has been developed (for example, Japanese Patent No. 3181997, JP-A-Hei. 10-211868, and JP-A-2001-349109). When the remote operation for locking/unlocking the door of the vehicle can be achieved at a place far from the vehicle, for example, a door unlock operation button provided in the transmitter may be pushed down accidentally, so that the door may be unlocked in spite of absence of the user from the neighborhood of the vehicle. Thus, the vehicle may be put in a state against the interests of crime prevention.
As a solution to such a problem, Japanese Patent No. 3181997 discloses technique in which the electric field intensity of a radio wave received by a receiver furnished in a vehicle is detected, a distance from a transmitter is obtained indirectly from the detected electric field intensity, and an unlock instruction from the transmitter is accepted only when the obtained distance is within a short distance range or a middle distance range. Japanese Patent No. 3181997 also discloses another technique in which the transmitted radio wave power from an antenna furnished in a transmitter is attenuated as soon as an unlock operation button provided in the transmitter is pushed down, so that a receiver furnished in a vehicle is prevented from receiving a radio wave including an unlock code when there is a long distance between the transmitter and the receiver. That is, Japanese Patent No. 3181997 discloses techniques for reducing the risk of theft while attaining a main object of achieving the remote operation of these functions (engine start and stop functions, and door lock and unlock functions).
JP-A-Hei. 10-211868 and JP-A-2001-349109 disclose technique in which remote operation for starting/stopping an engine of a vehicle can be carried out at a place far from the vehicle, while remote operation for locking/unlocking a door of the vehicle is prevented from being carried out at a place far from the vehicle. That is, JP-A-Hei. 10-211868 and JP-A-2001-349109 discloses technique, which attains a main object of achieving the remote operation of these functions (engine start and stop functions, and door lock and unlock functions).